Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Forest Tree Breeding, College of biological sciences and technology, Beijing Forestry University, Beijing, 100083, P.R. China.
Science and Technology Development Center, State Forestry Administration, Beijing, 100714, P.R. China.
Sci Rep. 2017 Nov 30;7(1):16637. doi: 10.1038/s41598-017-11859-w.
Gibberellins (GAs) participate in controlling various aspects of basic plant growth responses. With the exception of bryophytes, GA signalling in land plants, such as lycophytes, ferns and angiosperms, is mediated via GIBBERELLIN-INSENSITIVE DWARF1 (GID1) and DELLA proteins. To explore whether this GID1-DELLA mechanism is present in pines, we cloned an orthologue (PtGID1) of Arabidopsis AtGID1a and two putative DELLA proteins (PtDPL; PtRGA) from Pinus tabuliformis, a widespread indigenous conifer species in China, and studied their recombinant proteins. PtGID1 shares with AtGID1a the conserved HSL motifs for GA binding and an N-terminal feature that are essential for interaction with DELLA proteins. Indeed, A. thaliana 35S:PtGID1 overexpressors showed a strong GA-hypersensitive phenotype compared to the wild type. Interactions between PtGID1 and PtDELLAs, but also interactions between the conifer-angiosperm counterparts (i.e. between AtGID1 and PtDELLAs and between PtGID1 and AtDELLA), were detected in vivo. This demonstrates that pine has functional GID1-DELLA components. The Δ17-domains within PtDPL and PtRGA were identified as potential interaction sites within PtDELLAs. Our results show that PtGID1 has the ability to interact with DELLA and functions as a GA receptor. Thus, a GA-GID1-DELLA signalling module also operates in evolutionarily ancient conifers.
赤霉素（GAs）参与控制植物基本生长反应的各个方面。除苔藓植物外，石松类、蕨类和被子植物等陆地植物中的 GA 信号转导是通过 GIBBERELLIN-INSENSITIVE DWARF1（GID1）和 DELLA 蛋白介导的。为了探究这种 GID1-DELLA 机制是否存在于松属植物中，我们从中国广泛分布的乡土针叶树种白皮松克隆了拟南芥 AtGID1a 的同源物（PtGID1）和两个推定的 DELLA 蛋白（PtDPL；PtRGA），并研究了它们的重组蛋白。PtGID1 与 AtGID1a 共享保守的 HSL 基序用于 GA 结合和 N 端特征，这对于与 DELLA 蛋白相互作用至关重要。事实上，与野生型相比，拟南芥 35S:PtGID1 过表达植株表现出强烈的 GA 超敏表型。在体内检测到 PtGID1 与 PtDELLAs 之间的相互作用，以及松柏类-被子植物对应的相互作用（即 AtGID1 与 PtDELLAs 之间以及 PtGID1 与 AtDELLA 之间）。这表明松树具有功能性的 GID1-DELLA 成分。在 PtDPL 和 PtRGA 中鉴定出 Δ17 结构域是 PtDELLAs 内的潜在相互作用位点。我们的研究结果表明，PtGID1 具有与 DELLA 相互作用的能力，并作为 GA 受体发挥作用。因此，GA-GID1-DELLA 信号模块也在进化古老的松柏类植物中起作用。
